Surgical pump



1 1957 JEAN-LOUIS TREMBLAY 2,815,715

SURGICAL PUMP Filed llay 29, 1953 4 Sheets-Sheet 1 JEAN-Lows TREMBLAY(Inventor Attorneys l957 JEAN-LOUIS TREMBLAY 2,815,715

SURGICAL PUMP v Filed May 29, .1953 V 4 Sheets-Sheet 2 n m m m JEAN-L ISmsuaur 'n'ventor Dec. 10, 1957 JEAN-Louis TREMBLAY 2,815,715

SURGICAL PUMP Filed May 29, 1953 4 Sheets-Sheet s JEAN-LOUIS mavaurUm'aentor Dec. 10, 1957 JEAN-LOUIS TREMBLAY SURGICAL PUMP -Filed May 29,1953 4 Sheets-Sheet 4 JEAN-LOUIS TREMBLA) Jnven tor Attorneys 2,815,715Patented Dec. 10, 1957 SURGICAL PUMP Jean-Louis Tremblay, Quebec,Quebec, Canada Application May 29, 1953, Serial No. 358,4tl1

6 Claims. (Cl. 103-53) The present invention relates in general todevices for pumping liquids and more particularly to a blood pumpadapted to partially or completely replace the heart during surgicaloperations.

The general object of the present invention is the provision of asurgical pump of the character described so constructed and designed asto imitate as closely as possible the action of a human heart, or moreparticularly the action of a ventricle of the human heart.

A specific object of the present invention resides in the provision of asurgical pump which will have a sufficient rate of flow to be able toreplace, at least temporarily, the human heart during surgicaloperations.

Yet another object of the present invention is the provision of surgicalpump of the character described provided with valves similar in shape tothe mitral or tricuspid valves of a human heart and designed to preventdamage to the blood cells.

Still another important object of the present invention is the provisionof a surgical pump of the character clescribed the working speed ofwhich may be readily and very easily adjusted.

Still another important object of the present invention is the provisionof a surgical pump in which means are provided for adjusting the pulsepressure of the blood being pumped that is, the difference between thesystolic and diastolic pressures in the blood circulating system.

Still another important object of the present invention is the provisionof the surgical pump of the character described in which all theelements coming in direct contact with the blood being circulated, maybe very easily disassembled and sterilized.

Still another important object of the present invention is the provisionof a surgical pump which, due to its simplicity of design andconstruction, will give a prolonged service without any possibility offailure or interruption during surgical operations.

Yet another important object of the present invention is the provisionof a surgical pump of the character described the working volume ofwhich is very small relatively to the rate of flow of the pump, therebyrequiring only a small amount of transfusion blood for use inconjunction therewith.

The foregoing and other important objects of the present invention willbecome more apparent during the following disclosure and by referring tothe drawings in which:

Figure l is a perspective view of the casing housing Figure 6 is an endview of the check valve;

Figure 7 is a cross-section of the check valve taken through the lipsthereof;

Figure 8 is an enlarged fractional section of one pair of lips shown inclosed position; and

Figure 9 is a section similar to that of Figure 8 showing the lips inopen position.

Referring now more particularly to the drawings in which like referencecharacters indicate like elements throughout, the pump, according to theinvention, is preferably housed within the casing, generally indicatedat 1, and provided with a panel 2 mounting three knobs 3, 4 and 5 andthree switch levers 6, 7 and 8. The knob 3 serves to adjust the rate ofpulsating of the pump, the knobs 4 and 5 are respectively a coarse and afine adjustment of the pulse pressure of the circulating fluid. Theswitch 6 controls the operation of the rotary contactor device, theswitch 7 controls the filaments of the rectifying tubes and the switch 8controls the solenoid circuits of the medical pump.

The casing 1 is furthermore provided with a manometer 9 for indicatingthe pressure of the circulated blood. A cover 10, hinged at 10' may beopened for removing the pump assembly housed within casing 1. Thenumeral 11 indicates an electric cord for supplying electric current tothe pump, while the numeral 12 indicates one of the tubes connecting thepump to the heart of the person or animal being operated on.

Figure 2 shows the pump itself. The numeral 14 denotes an oil reservoirconstituted by a housing preferably of rectangular shape and made ofmetal. An oil filling opening 15 is made in the top 18 of reservoir 14and is normally closed by a threaded plug 16 engaging a collar 17secured to the top 13. An electric stirrer 19 is mounted on the plug 16and comprises an electric motor 20 secured to the plug 16 by means ofbolts 21, said motor having a driving shaft 22 passing through the plug16 and mounting a propeller 23 immersed in the oil 24 for circulatingthe latter around the pump solenoids in order to maintain the oil bathat a uniform temperature throughout.

The oil temperature is regulated by means of a water circulation systemcomprising the coil pipe 26 passing through the oil reservoir 14.

The two end walls 25 of the reservoir 14 are recessed inwardly in theirmiddle portion to form frustoconical cavities 27 apertured to receive arigid straight tube 28 made of nonmagnetic material and extendinglongitudinally through the reservoir 14. The tube 28 and walls 25 arewelded at their points of contact 29 to make leakproof joints. Threesolenoids 30, 31 and 32 are wound around the tube 28 inside the oilreservoir 14 and are separated from each other by discs 33 of insulatingmaterial. The solenoid 3G is evenly wound while the windings of bothsolenoids 31 and 32 are deeper towards the right hand side of saidsolenoids as viewed from Figure 2, in order to increase the magneticfield acting on the armtaure 34 as the latter moves towards the righthand side of the tube 28.

Two coaxial intercommunicating vessels or bellows 3S and 36 are mountedin tube 28. They are preferably made of natural rubber and have imbeddedtherein reinforcing threads 37 and 38 disposed circumferentially of thebellows portions of maximum and minimum diameter, respectively. Thearmature 34 is secured to the inner ends of said bellows and is slidablein tube 28, while the outer ends of the bellows are fixed with respectto said .tube.

The tube 28 projects at both ends within the recesses .27 and nipples 39and 1-0 are respectively secured to said projecting ends by means ofunions 4-1 and 42. On the outer ends of the nipples 39 and 4c arethreadedly secured caps 43 and 44 respectively having bores coaxial withthe tube 23 to receive the glass 'tubes 45 and 46 respectively.

The inlet and outlet flexible tubes 12 and 48 are respectively securedto the outer projecting ends of the tubes 45 and 46. Rubber bands 29 and50 surround .the abutting ends of the tube 12 and cap 43, and of thetube 48 and cap 14 respectively.

A rubber band 51 tightly surrounds the inner projecting end of the glasstube 45' in order to prevent removal of said tube 45 through cap 43.Similarly the inner projecting end of glass tube 46 is provided with anenclosing rubber sleeve 54 serving to prevent removal of said tubethrough the cap 44. The outer tubular end 55 of the bellows 36frictionally engages the rubber band 54 and abuts against the cap 44,while the outer tubular end 53 of bellows 35 frictionally engages thesleeve portion of check valve 52 which is in turn inserted over therubber band 51 on glass tube 45.

The communicating ends of the bellows 35 and 36 form abutting tubularportions 56 and 57 which extend within the cylindrical armature 34 andare in contact with the inner face thereof. A check valve 58 has atubular portion extending within the armature 54 and contacting thetubular portions 56 and 57 of the bellows 35 and 36. A thick rubbersleeve 59 is inserted Within the tubular portion of the check valve 58and exerts an outward I'Eh,

dial pressure against the inner face of the armature 34 therebypreventing disengagement of the bellows from said armature.

As shown in Figure 4, the armature 34 is made of two semi-cylindricalsections 60 and 61 having rabbeted ends 62 adapted to receive aretaining band 63, shown in Figure 2. The lower cylindrical portion 61is provided with a longitudinal groove 64 to permit air passage from oneside of the armature to the other during its reciprocal back and forthmovement within tube 28. The construction of the armature 34 permitsdisassembly of the bellows and the check valves for sterilization orrepairs.

The two check valves 52 and 58 are similar in construction and areillustrated in more detail in Figures to 9.

The tubular portion of said check valves is terminated at one end by aconical part 65, the apex 66 of which points in the direction of flow ofthe blood Within the pump. Said conical part 65 is provided with threeequally spaced longitudinally extending slits 67 each defined by a pairof lips 68 each of which forms an integral outward longitudinalprojection of the conical part 65. The inner face 69 of each lip 63 of apair is substantially flat to contact each other over a substantialarea, as shown in Figure 8, when said lips are in closed position. Thelips are outwardly tapered to form a thin free edge 70 and they arenormally urged in closed position due to the resiliency of the rubberfrom which they are made. It will be noted that the shape of the lips 68is similar to the shape of the lips of the mitral or tricuspid valves ofa human heart. Due to the relatively large contact area between the lips68 and consequently due to the limited pressure per unit area on saidcontacting surfaces, the blood cells trapped between the lips when thelatter are in closed position will not be damaged.

From the foregoing description, the operation of the pump, according tothe invention, will become apparent: Upon energization of the leftsolenoid 30, the armature 34 will move to the left whereby the bloodalready in bellows 35 will pass through check valve 58 into the righthand side bellows 36. During this return stroke corresponding to thediastole of the human heart, there is no blood actually dischargedthrough the outlet tube 48, and the blood is prevented from flowing backinto inlet tube 12 because the pressure is acting in a direction toclose the check valve 52.

Upon simultaneous euergization of the solenoids 31 and 32, the armature34 is displaced towards the outlet tube 48 thereby pumping out the bloodinside bellows 36 and at the same time creating a suction within bellows35 to admit blood therein through the inlet tube 12 and check valve 52.During this compression stroke corresponding to the systole of a humanheart, the check valve is closed.

Figure 3 shows a manner of connecting the surgical pump to a human heartin which case the blood is in a large part derived from the heartthrough the pump and through an artificial lung schematically shown atB. The inlet tube 12 is connected to the inferior vena cava C while theoutlet tube 48 passes through the lung B and is connected to the arch ofthe aorta at 47.

Of course other types of connection may be effected, for instance, theinlet tube 12 may be connected to one of the pulmonary veins D, in whichcase no artificial lung would be required.

Figure 3 shows also a preferred manner of energizing the solenoids 30,31, 32. The electric cord 11, shown in Figure 1, is connected to asupply of alternating current and may be provided with a main switch 71.An electric motor 72 is connected to the cord 11 and its driving shafthas a worm meshing with a worm wheel 73 driving a rotary contactor 74 ata speed which may be adjusted by the knob 3 on the panel 2 of thehousing 1, as shown in Figure 1, which controls a governor 75 secured tothe motor 72. The outer surface of the contactor 74 is made of electricconducting material except for two longitudinal side strips 76 and 7'7respectively extending on opposite portions of the contactor for an arcof approximately 150 and 210, and corresponding to the respectiveduration of energization of the return stroke solenoid 30 and of thecompression stroke solenoids 31 and 32. Stationary contacts 73, 79 andare respectively mounted to contact the middle portion and each side ofthe rotary contactor 74 so that the middle contact 78 will always beelectrically connected to said contactor 74 while the contact 79 will bedisconnected when contacting the insulating strip 76 and the contact 80will be disconnected when passing over insulating strip 77.

The electric cord 11 feeds a double transformer 81, the primary winding82 of which is connected in series with a rheostat 83 for varying thevoltage across the same. One terminal of the winding 84 of saidtransformer is connected to the terminals 85, $6 and 87 of the solenoids30, 31 and 32 respectively and also to contact 78 of the rotarycontactor 74. The other terminal of the secondary winding 84 isconnected through switch 7 to the anodes of the rectifying tubes 88 and89 and also to one terminal of the windings of relays 9t) and 91. Theother terminals of said relays are respectively connected to thecontacts 79 and 80.

The other secondary winding 92 of the transformer 81 is connectedthrough switch 8 to the filaments of the rectifying tubes 88 and 89 forenergizing the same.

The second terminal 95 of the solenoid 30 is connected to the cathode ofthe rectifying tube 89 by passing through the armature 96 of the relay90. Similarly, the second terminals 97 and 98 of solenoids 31 and 32 areconnected to the cathode of the rectifying tube 88 by passing througharmature 99 of the relay 91.

The rectifying tube 88 has a grid 100 positively biased by means of thebattery 1G1 and rheostat 102.

The rheostat 83 is controlled by knob 4 of panel 2 of the pump casing 1and serves as a coarse adjustment of the intensity of energization ofthe solenoids 30, 31 and 32, while the rheostat 102, controlled by knob5 shown in Figure 1, serves as a fine adjustment of the current passingthrough the solenoids 31 and 32.

In the position of the rotary contactor 74 shown in Figure 3, solenoid30 is de-energized while the solenoids 31 and 32 are energized throughthe following circuit: terminals 36, 37, secondary winding 84, switch 7,tube 88, relay armature 99 and terminals 98 and 97. The

relay 91 is maintained in circuit closing position by the circuit;secondary winding 84, relay 91, contact 80, rotary contactor 74, contact78 and secondary winding 84.

When the rotary contactor 74 has turned through a certain angle from theposition shown in Figure 3, the electrical connection between contacts811 and 78 is broken de-energizing solenoids 3i and 32, and electricalcon-- nection between contacts 78 and 79 is established therebyenergizing the relay 90 which closes relay armature 96 and thereforecloses the energizing circuit of solenoid 30 through rectifying tube $9.

From the above described arrangement it will be seen that theenergization of the two groups of solenoids is effected alternately,corresponding to the compression and return strokes of the pump.

The pressure exerted by said pump may be contrcled by rheostats 83 and102, and is indicated on manometer 9 connected to the outlet tube 48.

The speed of the pump pulsations is easily controlled by the governor 75of the motor 72 through the means of the knob Si.

in the embodiment described, the solenoid 30 is wound in a directionopposite to the direction of winding of solenoids 31 and 32 so as toproduce a magnetic field causing the return stroke of armature 34.

It should be noted that the distance travelled by the soft iron armature34 does not need to be of great length to pump the blood at a rate offlow equal to that of the human heart. In practice the armature 34- willmove from its center position, shown in Figure 2, in the middle or"solenoid 31 to a right limit position across solenoids 31 and 32 due tothe taper of said solenoids, and will return to a left limit positionsubstantially in the middle of solenoid 30.

in order to obtain frictionless working of the bellows 35 and 36 and ofarmature 34 within tube 38, the latter may be lubricated by a suitablepowdered lubricant such as talc powder.

While a preferred embodiment according to the present invention has beenillustrated and described, it is understood that various modificationsmay be resorted to without departing from the spirit and scope of theappended claims.

I claim:

1. A surgical pump comprising a tube of nonmagnetic material, at leasttwo solenoids wound around said tube longitudinally of said tube,electrical means for alternately energizing said solenoids duringunequal periods of time to create a magnetic field through said tubealternating for unequal periods of time from one portion of said tube toanother portion of said tube, two bellows disposed within said tubehaving their outer ends secured to the outer ends of said tube andhaving their inner ends in communication with each other, a cylindricalarmature of magnetic material secured around the communicating ends ofsaid bellows and slidable back and forth within said tube under theaction of said alternating magnetic field, a check valve secured withinsaid bellows adjacent their communicating ends and a second check valvesecured near one of said outer ends of said tube and disposed within thecorresponding end of one of said bellows, said check valves beingoriented to permit circulation of liquid from said last to said firstmentioned check valve and to prevent circulation of said liquid in thereverse direction, a housing surrounding said solenoids and secured tosaid tube, a liquid bath in said housing, in which said tube andsolenoids are immersed and means to maintain said liquid bath at aconstant temperature.

2. A pump as claimed in claim 1, wherein the winding 3. A surgical pumpcomprising a casing provided with open ends, two coaxial fluid receivingbellows disposed within said casing, communicating with each other atone end and having their other outer ends fixed to the open ends of saidcasing to provide for fluid flow, an armature made of magnetic materialsecured to and surrounding said communicating ends of said bellows, atleast two solenoids spacedly wound around said bellows and coaxialtherewith, an electric supply circuit for each of said solenoids,contactor means in each of said circuits, means to close said contactormeans alternately and for unequal periods of time whereby said solenoidswill be energized for unequal periods of time and will generate amagnetic field displacing said armature back and forth, and two checkvalves disposed within said bellows, one of which is secured near thefixed end of one of the bellows and the other is secured to thecommunicating ends of said bellows, both said check valves beingoriented to block fluid circulation from said last named valve to saidfirst named valve and to permit circulation of said fluid in the reversedirection.

4. A pump as claimed in claim 3, wherein said check valves consist of asleeve of elastic material forming a closed conical portion at one end,said conical portion having longitudinal slits and lips extending oneach side of said slits, said lips having an inner surface adapted tocontact with each other to close said slits.

5. A surgical pump comprising a casing provided with two open ends, twocoaxial liquid receiving bellows disposed within said casing in axialalignment, communicating with each other at one end and having theirother outer ends fixed to the open ends of said casing to provide forfluid flow, two check valves disposed within said bellows, one of whichis secured near the fixed end of one of the bellows and the other issecured to the communicating ends of said bellows, both said checkvalves being oriented to block fluid circulation from said last namedvalve to said first named valve and to permit circulation of said fluidin the reverse direction, a cylindrical armature made of magneticmaterial secured to and surrounding said communicating ends of saidbellows, and slidable within said casing, two groups of solenoids woundaround said casing longitudinally thereof, one group of said solenoidscreating a magnetic field to displace the armature in a direction tocause the compression stroke of said pump and the other group of saidsolenoids creating a magnetic field to displace the armature in thereverse direction corresponding to the return stroke of said pump,electric supply circuits connected to said respective groups ofsolenoids, contactor means in each of said circuits, and means to closesaid contactor means alternately and for unequal periods of time, saidlast named means closing the contactor means of the circuit of said onegroup of solenoids for a longer time than the contactor means of thecircuit of said other group of solenoids whereby the compression strokeof said pump will last longer than the return stroke of said pump.

6. A pump as claimed in claim 5 including means to adjust the speed ofoperation of said closing means to thereby adjust the speed of thereciprocable back and forth movement of said armature.

References Cited in the file of this patent UNITED STATES PATENTS (Nonumber) Whitfield June 2, 1836 1,580,479 Frankenfield Apr. 13, 19262,061,869 Gilbert Nov. 24, 1936 2,194,535 Von Delden Mar. 26, 1940FOREIGN PATENTS 547,566 France Sept. 26, 1922 597,046 Great Britain Jan. 16, 1948 928,381 France June 2, 1947

